Due to the bursty nature of non-real-time (NRT) services, the allocation of physical resources for NRT services is also bursty and short. For each allocation, the accuracy of initial downlink transmit power is important to the experienced quality of service, such as the block error rate (BLER), of the allocation. Currently, the initial downlink transmit power is estimated by the controlling radio network controller (C-RNC) using two different schemes according to the availability of measurements.
Due to factors such as fading, mobility, measurement reporting delay, and errors, the initial downlink transmit power can be significantly different from the actual required power to support the signal to interference ratio (SIR). If the initial downlink transmit power is significantly lower than the actual required power, the actual SIR in the beginning of the allocation will be much lower than the required SIR, which will cause many transmission errors. Since the allocation for NRT services is usually short, errors encountered in the beginning of the allocation may not be averaged out through the short allocation duration to meet the required BLER.